What Can I Do About The Issues I'm Having With My Ex And My Daughter?

Six years old is very late for your daughter not to be exercising regular toiletry habits and still be using diapers unless there is a medical condition that requires it.  I cannot imagine Social Services ignoring your requests, but my next suggestion is to speak with a mental health professional who specializes in pediatric mental health, and perhaps even facilitate a meeting between all of you to discuss and come to solution.  There can be significant emotional damage to a child who is of socializing age (school and friends) and is perceived to be so different from others, which can be permanent.  Perhaps if you all cannot come to agreement and course of action with this professional, he or she may be willing to write a letter of recommendation based on her professional opinion, which can be presented and honored by the courts for a change of custody-- or another care order which can change the situation, centered  on the well being and future well being of your child.